Tim D'Annecy

Using chflags in FreeNAS

I was trying to protect a file in a jail on my FreeNAS server but the chmod +t tag wasn’t
cutting it for me. I wanted to use flags to protect the file, a common practice in FreeBSD
and other POSIX systems.

I tried running chflags schg foo.bar, but the terminal spat out “Operation not
permitted.” I was puzzled. There are multiple instances where chflags support was added to
ZFS many versions ago so I didn’t understand why I couldn’t use the feature.

I found out that the default FreeNAS jails template creates jails without support for
changing flags. I had to go into the web interface and open up my jail instance, open the Advanced Settings, and add allow.chflags=1 to the Sysctls field.

Make sure you have a comma separating any other existing configuration and that you restart
the jail for the changes to take effect.